Fig. 4.

PQ treatment did not affect insulin-dependent activation of PI 3-kinase. Primary cultured rat hepatocytes were pre-treated with 0, 2, or 5 mM PQ for 6 h and then treated with/without 100 nM insulin for 1 min. Protein lysate was prepared from the cells, immunoprecipitated with anti-IRS-1 antibody (A) or anti-IRS-2 antibody (B), and PI 3-kinase activity was analyzed by measuring ³²P incorporation into phosphatidylinositol (upper panels). ³²P incorporated into phophatidylinositol 3,4,5-triphosphate was quantified and expressed as relative values to cells treated without insulin and PQ (Ins-, PQ 0 mM) (lower panels). Values are means ± SEM of three dishes. #Significantly different from cells without insulin treatment (p<0.05).